Chinese Patent Application No. 97120142.0 (US pending application Ser. No. 08/872,416) disclosed a fire-safe Halogen Torchiere Lamp with a grid, a thermal sensor, a photo sensor, an electronic circuitry to provide automatic cut-off function of the power supply when the above sensors sensing a preset value, and a mechanical switch for cutting off the power supply when the lamp is tipped over to a preset angle.
The first disadvantage of the prior art tipover switch is a follows. Since such a mechanical switch is located on the under-side of the base, and must positively contact the floor surface, it is always an offense against any safety law to install a power switch in this location. Besides, if the switch is used directly to cut-off the power supply, since one conductor of the power cord must be cut in such a low position for connecting the switch, then strain relieves must be put on both sides of the switch. The connecting means (which are also very near the floor surface) should be insulated with water proof grade materials because the floor surface is always splashed with water.
The second disadvantage of prior art mechanical switch is that, even if the above switch is used for cutting off the signal circuit, since the stroke of the mechanic switch plunger has fixed value, one design can not be used for all lamps. For example, even if the switch is located in the center of the base, if the base diameter is changed, since the stroke of the switch plunger is a constant, the tipover angle will change the accordingly.
The third disadvantage is that, if the torchicere lamp equipped with a prior art switch is successively pushed-pulled by a child to cause the switch to turn ON and OFF successively in a very short time period, the switch will break down at once. The reason is that the majority of the switches are designed to turn ON and OFF less than 50 times in one hour, not in one minute. Accordingly, it always causes trouble in manufacturing a new torchiere lamp or to reform an old torchiere lamp for complying with the tipover-safe requirement of new UL-153 with a prior art tipover-safe switch.